I am tirelessly working away on getting my plans together for my kegerator, and I had a few questions on the gas side of things.

Right now my setup is as such: I have a CO2 tank with a primary regulator connected. Then I have a CO2 line run from the regulator to my secondary chain on the chest freezer. My question is with this gas line connection. I am using push connect fittings from McMaster, such as part number 51025K178. However, I've never used, much less seen a push connect fitting in real life. How secure is it's hold on the gas line? If I bump into it, is it going to fall out? I imagine I'll probably have like 80-100psi running through it from the primary reg.

Also, I might have a ball valve between the primary reg and the push connect fitting, just so I can shut off CO2 to the line to the secondary regs. Let's say I want to replace the line or take it off for some reason, the line is still going to be pressurized to 100 psi even though the tank is shut off. Can I pull the line out of the PC fitting safely under this pressure? Ideally, I'd prefer to have a line vent valve of some sort, but I can't find anything in McMaster. I'm probably not looking in the right place.

I can't help you with the push fitting, but I'd say you can probably do without it if you have to. I almost used a quick-release air hose with my set up, for ease in changing tanks, but in all honesty, I just remove the whole primary regulator when I need to take it out, leaving the regulator connected to everything else. I was worried my connection would slowly leak, which is an unfortunate thing to find out when you go for a cold draft.

Regarding your out-pressure from your primary reg, there's no need to have it that high. It only NEEDS to be the pressure of your highest-set secondary regulator. I have mine set around 30 PSI, with my secondarys set from about 25 down to 5 PSI. Except for the very first time it's hooked up, it'll never have to pump hard enough to warrant 80 or 100 PSI, and even then it's more a matter of waiting a few minutes while the system equalizes... Plus you're getting into the danger zone with that high a setting, which leads us to your ball valve...

With your ball valve theory, yes... when you turn the pressure off to your secondarys, you'll have a little stored pressure in the lines. You can pull on a keg pressure valve and release it, or, assuming it's not set at 100, just disconnect it without any precautions... it'll hiss for a second, but that's it. The tube will have a high psi but low volume.

*edit*
Oh, and if you disconnect from your primary, with nothing on the keg end to also seal the pressure (I have ball/check valves exiting every secondary reg), you'll instantly drain all the co2 in every one of your kegs, leading to a very messy situation, very rapidly. Probably some ruined secondary regulators as well. Northern Brewer has some good ball/check valves. A good idea regardless.

Barb connectors are quite secure, if you use the correct sized gas line.

I have shut offs on all of my lines (and check valves at the regulators), but you could just pull the gas lines off of the kegs before doing maintainance.

And I agree that 30-35 psi is plenty from the primary regulator. I run mine at 35 mainly to supply the soda water tank with extra fizz.

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